Fluid power transmission



VMarch 211939. A. BERGER 2,151,075

FLUID POWER TRANSMISSION lFiled lieb. 2s, 1958 s sheets-sheet 1 772 i 0 nveni ARH/095mm? vMarch'IZl, 1939. i l BERGER v2,151,075

FLUID POWER TRANSMISSION Filed Feb. 26, 1938 3 Sheets-Sheet 2 March 21, `1939. I A BERGER 2,151,075

I FLUIDPowER TrmNsMIs'sIoN` v Filed Feb. 26, 1938 ISSheets-Sheet 5 //z/@Bmam ff a a? M Patented Mar. i939 A UNITED STATES PATENT ottici?. y FLUID rowiiltslrnsmssroiv l Arthur Berger, Obertrkheim, near Stuttgart,

Germany many Application assigner to Daimler-Benz gesellschaft.. Stuttgart-Unterturkheim, Ger- Febmuy 26, 193s, serial No. 192,711

In Germany February l23, 1937 transmission and is particularly' concerned vwith such a transmission when applied to the driving of super-charging blowers of'internal combusv tion engines.

lOne object of the invention is to provide a combination of two or more fluid transmissions with slip control means whereby a variable transmission is' achieved. n

in series with slip control means adapted for conktrolling the several transmissions in dependence s One advantage of the invention over a single fluid transmission device is that the slip in in ingslipi is avoided. Furthermore, the invention enables a graduation of the total slip, and consequently of the power transmission or transmission ratio, to be achieved in a' simple and re- `liable manner by a, partial emptying of the transmission devices in succession.

Further objects and features will appear fron'rthe description of the annexed drawings which illustrate twoy arrangements in accordance with the invention, these being given by way of example only.

In the drawings: g Figure 1 is a more or less diagrammatic 1ongitudinal sectional elevation .oi a blower driven through a transmission comprising two iiuid transmission devices in series; v

Figure 2 vis a diagrammatic view showing a vices; Y Figurev 3 is alongitudin'al elevation partially lin cross-section of -a `modiled`type of valve con- 'trol as usedA with the valve illustrated in Fig.v 1; Figure 4 is a. longitudinal elevation partially in cross-section of'still a 'further form of .valve control vwhich may be used in' combination with the valve shown in Fig.l l;

- Figure 5 is a longitudinal elevation partially in cross-section of a modiied'pump and control arrangement whichl may be used in place o! that illustrated in Fig. 2; yFigure 6 is. ay longitudinal elevation partially in vcross-section of a modied valve arrangement Another object is to provide uid. transmissions I heating increases extremely quicklyjwith increasmodiiied control for the .iluid transmission v.de-

which may be used in place of that shown in Fig. 2; and

Figure 'I is a still further modiied control arrangement for use with my transmission'.A` Referring to Figure 1, agis a, driving shaft, 5

for example the crank shaft of an internal combustion engine or a shaft driven thereby which, through two gear wheels b and bl drives a shaft c at higher speed than the vspeed of rotation of shaft a. The latter is coupled by-two fluid trans- 1o vmissions d and e,. connected in series, to the shaft f of the blower impeller a;

The iluid transmissions d and e are constructed after the fashion of Fttinger transmissions and consist of a driving half `h iixedly connected to the shaft c,a middle part i driven thereby, .this part including both the driven half of the first transmission d and the driving half of the second transmission eand a driven transmission .half l of the second transmission e xed on .20 the'blower shaft f. The middlepart i constitutes part of a structure that includes a transmission, housing k, thelatter` being either revolubly mounted in fixed bearings or, as shown, adapted for running on bearings on the shaft parts.

'I'he operation of the above described arrangement will be obvious to those skilled in the art and need 'not be discussed in detail. The shaftl c being driven from the engine through gears b and b1 drives the member h. If iluid is present between. the member h and the member the member h will act as anV impeller to drive the free intermediate member i acting as a turbine.` This free member also includes a partvv which, under the properiluid conditions, will act as an impellerdrivi'ng the driven member l connected to the blower g. vlli? the transmissions d ande are both lled with fluid, there will accordingly be a direct power connection between the engine and blower..

The transmission 'assembly is arranged inside a casing m which is connected by a return pipe l n to a vessel o, here illustrated as an engine o il back to the vessel o by a return passage t when pletely emptied.

Viiows back directly into the vessel o.

the transmission is ineffective and the blowerA the transmission is to be idle. Y

From the passage r, the liquid is supplied to the pipe u and the'annular passage o in the shaft c and by radial ports w to the interior of the transmission d, whilst the oil supplied through the passages is conducted through an-'inner tube :1: and radial ports y to the clutch e. Small ports or throttles z in the transmission housing 1c permit of outiiow of theliquid from the transmis-l In the illustrated position of the cock q (posi-:

tion II of the control lever), both passages 1' and s are. in full communication with the liquid circulation so that the two fluid transmissions are filled and have a minimum slip for the maximum transmission of power. The blower g then runs at high speed.

By turning the cock q to the leftA or counterclockwise, the flow of the liquid to the passage s and, therefore, to the transmissione is more or less throttled. The transmission e consequently then runs partly empty so that an increased slip arises between the transmission halves i and I,

whilst the transmission dis still completely iilled.v

Consequently the blower runs with the speed substantially reduced by the slip of the transmission e. In the limiting case (position I of the control lever),. the passage s Ais completely closed and the transmission e may become com- Ii' thecock q is turned to the right, then conversely the flow oi the liquid to the passage r and,

therefore, to the transmission' d is throttled so' the speed of the blower to be reduced substantially below the maximum speed, owing to the slip of the transmission d.

By yet further adjustment of the cock q to the right (position III of the control lever), first of all the transmission d is cui. ofi completely and thereafter also the transmission e (position IV), whilst at the same time the return passage t is opened so that the liquid delivered by `the pump p In this case,

runs idly.

With the circuit illustrated in Fig. 2, separate pumps pi and p2 and also separate control cocks q1 and q2, which are actuated by a common linky age qs, are provided for eachl passage ri, si.

In the illustrated position, the passages r1, s1 and consequently the fluid transmissions .d and c are in full communication with the circulation. By displacing the linkage qa rto the left, first of all the passage s1 is4 throttled and the lling of the transmission e is thus reduced. vOnly after a certain displacement, is thetransmission d also cut off by gradual closure of the4 passage r1 until ultimatelyA both transmissions run empty. At the same time, the return passages t1 and t2 are opened to a corresponding extent by the cocks q1, q2 so that the liquid supplied by the pumps p1', p2 flows back in part, and finally wholly, into the vessel 0.

As an example of the automatic valve adjusty eratively connected with the valve q through the connecting rod qs. Pressure of the blower is transmitted tothe bellows 71 by suitable means here indicated as 'conduit t.

'I'he arrangements illustrated in Figs. 3 and 4 have been drawn in connection withgthe single `valve arrangement illustrated `in Fig. 1. It is obvious, however, that they maybe used with the double valve arrangement shown in Fig..2. If,

moreover, it is desired that each of the valves qi and q2 (Fig. 2) be separately controlled by separate pressure responsive devices, an arrangement such as shown in Fig. 5 may be used. In this such as a connecting rod q'3 while the valve q1 is interconnected with the bellows 5": bythe connecting rod q"3. The arrangement illustrated in Fig; 5 shows a variation of that illustrated in Fig. 2. In Fig. 5 the separate pumps p1 and p2 have been replaced by asingle pump pa.

Fig. 6 illustrates another simple modiication of my control system. Instead of providing separate conduits ti and tz leading directly from the valve as in Fig. 2, these outlet conduits may be connected directly with the supply conduit from the pumps through the medium of spring loaded valve t'i and tz respectively. Accordingly, in the arrangement shown'in Fig. 6 the valves q1 and qz will act solely to cut off 'or turn the supply of fluid from .the pumps p1 and p2 to the supply conduits n and s1. When these valves are in their closed i position, the pressure will build up in the conduits leading from the pump, and when it has reached a predetermined amount, the valves t'1 `and tz willopen, thus permitting free circulation of the iluid to the sump o through the outlet conduits t1 andtz. This arrangement is the full equivalent of that illustrated in Fig. 1 but makes the construction of the valves q1 and q'z considerably simpler and in some cases, may be desirable.

In the modified arrangement illustrated in Fig. 7 the control valves q1 and q2 have been entirely eliminated. Control of the pump fluid supplied to the transmission is effected solely by control clutches qi and qz driving the pumps p'i and p'z respectively. By suitable operation of the con'- trol or connecting rods qa and q"3 the clutches q'1 and qz may be operated in any desired manner to drivably connect or disconnect the fluid supplying pumps.

While I have illustrated and described certain improvements of my invention, it is to be understood that I am not limited, thereto except as may be required by the claims which follow.

I claim: l l. A fluid transmission for interconnecting a load and a source of power, comprising, in combination, an impeller elementconnected to the source of power. a'turbine.. element connected to the load, a free member intermediate .said impeller and turbine elements, including a second Aturbine element cooperating with said impeller element to form a iirst working circuit, anda isecond impeller element cooperating with said rst turbine element to form a second working circuit, separate'conduits for respectively supplying fluid to said rst and said second working circuits, and means for controlling the supply oifluid to said separate conduits.

2. The combination according to claim l, in which said last means comprises avalue device common to both conduits. f

3. The combination accordingto claim 1', ,in

which said last means includes means for sup- Y anims plying i'i'uid to one conduit in advance of the supply to the other conduit. t

4.v The combination according to claim 1, in combination with a single casing enclosing said entire transmission vand attached for movement with s aid free intermediate member, and means for rotatably supporting said casing.

5. A uid transmission comprising, in combination, a driving shaft, an impeller element connectled for rotation therewith, a driven shaft, a tur'- bine element connected therewith, a free member intermediate said impeller and turbine elev ments, including a second turbinel element coopf erating with said impel1er-element to form a irst working circuit, and a second impeller element cooperating with said'rst turbine element to form a second working circuit, a casing attached to said free intermediate member and enclosing the entire transmission, and bearings on the said driving and driven shafts for rotatablysupporting said casing. Y s

6. A uid transmission for interconnecting 'a load and a source of power, comprising, in combination, an impeller element connected to the source of power, a turbine element connected to the load.- a free memberintermediate said impellerand turbinefelements, including a second clutches.

second impeller element cooperating Awith said iirst turbine element to form a second working circuit, fa casing .attached to said free intermediate member 'and enclosing the entire transmis'- casing.

'1. 'Ihe ,combination according to claim 1, in which said last means comprises ra valve adjustable to supply iuidl to either, both or neither oi' said conduits.

8. The combination according to claim 1, in

turbine element cooperating with said impeller elementto form a iirst working circuit, and a sion, vand means for rotatably'supporting said l which said last means comprises a pair ofv rotatable valves, one in eachA conduit, and control means correlating and interconnecting said valves in such-a manner that uid may be supplied to A ARTHUR BERGER.. 

